Magnetic character printing head



y 28, 1968 J. c. SIMS, JR 3,386,101

MAGNETIC CHARACTER PRINTING HEAD 7 Filed Sept. 15, 1965 2 Sheets-Sheet 1FIG. 1

y 8, 1968 .J. c. SIMS. JR 3,386,101

MAGNETIC CHARACTER PRINTING HEAD Filed Sept. 15, 1965 2 Sheets-Sheet 2FIG. 3

COMPUTOR FIG. 5

United States Patent 3,386,101 MAGNETIC CHARACTER PRINTING HEAD John C.Sims, In, Sudbury, Mass, assignor to Sperry Rand Corporation, New York,N.Y., a corporation of Delaware Filed Sept. 15, 1965, Ser. No. 487,418 7Claims. (Cl. 34674) This present invention relates to an electromagnetictransducer useful in producing original typographical latent magneticimages.

In many cases it is desired to create typographical latent images whichare not to be reproduced from preexisting typographical originals, butwhich are to be translated from coded electric signals transmitted to aprinter either from some remote point or from computing and businessmachines as the result of their manipulations and computations.

Accordingly, it is a primary object of this invention to provide animproved type of magnetic transducer or head structure capable ofinstantaneously recording the complete magnetic images of wholecharacters.

Further objects of the invention will become apparent from the followingspecification in conjunction with the accompanying figures in which:

In the drawings:

FIGURE 1 is a perspective view of an electromagnetic recording head inaccordance with the invention;

FIGURE 2 is a perspective view illustrating elements of the recordinghead;

FIGURE 3 is an enlarged front view of the recording head shown in FIGURE1 and illustrating the magnetic image array of one character;

FIGURE 4 is a fragmentary perspective View illustrating a modified formof the invention; and

FIGURE 5 is a fragmentary end view showing a portion of the printingcylinder used with the head.

Now with attention to the details of the various figures of drawings, itis seen that the transducer or head comprises a plurality of comb-likemembers 12 each of high magnetic permeability, which might be made, forexample, of soft iron, or the well known alloys such as those sold underthe trademark Hypersil or Permalloy. Each member 12 is provided alongone edge with a plurality of tines 14 having gaps or notches 16therebetween. For the purpose of illustration, and as a matter ofpreference, fifteen gaps are shown (FIGURE 3).

A plurality of the comb members 12, twenty in this case, are arranged ina stack with a slight space 18 between each pair. While otherarrangements may be utilized, it is preferred to stack them in abox-like frame 20 with their opposite ends received in grooves 22 formedin the inner faces of the opposite side Walls 24 and 26, and preferablywith the tines and notches vertically aligned. When used with a drum 28,as seen in FIGURE 5, the front face of the head is curved complementaryto the curvature of the drum and closely spaced therewith. The largenumber of gaps or notches produces better character definition, but moreor less may be used as the occasion demands.

In this preferred form of the invention, a separate wire 29 is threadedthrough appropriate notches 16 in the shape of and for each letter ofcharacter to be printed. By way of example, to form the letter B a wireis threaded through the gaps 16 identified on FIGURE 3 by the circles 30leaving the terminals 32 for connection with a suitable pulse source,such as a computer 33. It has been found that the use of a No. 36 wireto form each image and a twenty ampere pulse for one to fivemicroseconds is quite satisfactory.

As indicated =at 34 on FIGURE 2, connection of the terminals 32 withsuch a pulse, effects a flow of magnetic flux across the ends of thegaps 16 traversed by the wire forming the particular character. In thecase of the letter B as seen in FIGURE 3, it would be at those gaps inthe circles 30 defining the letter in this figure. In accordance withthe method disclosed in the Eckert et al. Patent No. 3,012,232,corresponding spots on the drum or printing cylinder 28 are magnetizedby this flux. These spots are then developed by subsequent exposure to asuitable magnetic ink, usually in powder form, which is transferred fromthe drum to a sheet or web of paper, or other suitable printing medium,thus to print visible characters. Printing, of course, could take placedirectly upon a magnetic sheet or web, in which case the head face maybe planar.

Instead of individual heads, such as shown in FIGURE 1, at each printposition in a line of characters, the transducers for all printingpositions may be in one unitary construction, as shown in FIGURE 4. Inthis form the combs 12 are of a length to extend across all printingpositions, but with .the individual character forming wires utilizingonly those gaps suflicient to define any one of the characters to beprinted at each position. This is particularly advantageous in that onewire may be threaded throughout the length of the transducer to form acomplete one line message, or for underlining up to a whole line ofprinting. Spacers may be provided between the combs at intervals alongtheir lengths to hold the combs aligned.

In a modified form of the invention, instead of the single wire to formthe characters, the base portions 36 of the members 12 in the areascorresponding to the respective gaps 16 are wound with separateenergizing coils 38. While a coil may be provided at each of the gaps,it will be obvious that it is more economical to provide them only atthose gaps used in the formation of the characters to be printed.

In this case, each of the members 12, is similar to the transducer shownin FIGURE 1 of the above mentioned Patent No. 3,012,232.

Preselected leads 40 from the ends of separate energizing coils 38 ofeach member are connected in series, as indicated by the broken lines 42in FIGURE 2 and according to the characters to be printed, each head, asmentioned above, contains all of the characters.

By way of example, to form the letter B, all of the coils 38 at the gapsidentified by the circles 30 on FIG- URE 3 are series connected in asingle circuit with the terminals 32. Similarly, the coils 38 areinterconnected in series circuit in each head to form all othercharacters of a font. Obviously some coils will be used for more thanone character or image. The number of turns per coil and the electriccurrent required is dependent upon the material used in the printingcylinder or drum 28 (FIG- URE 5) and the flux density required forproper magnetization on the surface of the drum in accordance with theprinting method disclosed in the above identified patent.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:

1. A magnetic transducer for instantaneously recording magnetic imagesor characters on a magnetic surface, comprising:

(A) a plurality of comb-like elements of high magnetic permeability,each having alternate tines and notches along one edge;

(B) means for holding said comb-like elements in stacked relation, oneover the other with the tines and notches facing in the same direction;

(C) electrically conductive means threaded through certain of thenotches in the shape of a character or image to be recorded; and

(D) means for connecting the said electrically conductive means to apulse of electrical energy thereby momentarily to induce a flow ofmagnetic flux across the ends of each notch traversed 'by said pulsedelectrically conductive means, whereby the character or image formed bythe electrically conductive means may be magnetically recorded on aclosely spaced magnetic surface.

2. A magnetic transducer according to claim 1 where- (A) the tines andnotches of the comb-like elements are vertically aligned.

3. A construction according to claim 1 wherein:

(A) the holding means comprises a rectangular frame having side walls,the inner surfaces of which are notched to receive the opposite ends ofthe comblike elements.

a 4. A magnetic transducer according to claim 1, where- (A) theelectrically conductive means is a wire.

5.v A transducer in accordance with claim 1, wherein:

(A) a plurality of electrically conductive means is threaded through thenotches of said comb-like elements one upon another in different pathsthus to form a plurality of characters or images for selectiveconnection to the pulse source, whereby the one transducer may be usedsuccessively to record the same or different characters or images.

6. A magnetic transducer according to claim 1, where- (A) said comb-likeelements are elongated to accommodate a plurality of characters orimages formed 3 by individual electrically conductive means threaded '4through said notches in side by side relation whereby a whole line ofcharacters or images may be recorded simultaneously.

7. A magnetic transducer for instantaneously recording magnetic imagesor characters on a magnetic surface, comprising:

(A) a plurality of similar comb-like elements of high magneticpermeability each having alternate tines and notches along one edge;

(B) frame means for holding said comb-like elements in stacked relationslightly spaced one over the other with the tines and notches facing inthe same direction and vertically aligned;

(C) individual electrically conductive Wires threaded through certain ofthe notches of each wire in the shape of a character or image to berecorded; and

(D) means for selectively connecting each of the said wires to a pulseof electrical energy thereby momentarily to induce a flow of magneticflux across the end of each notch traversed by said pulsed wire, wherebythe character or image formed by the selected wire may be magneticallyrecorded on a closely spaced magnetic surface.

References Cited UNITED STATES PATENTS 3,254,626 6/1966 Uemura 346-743,012,839 12/1961 Epstein et a1. 178-30 3,012,232 12/1961 Eckert et al.34674 2,950,161 8/1960 Rueger 346-74 2,820,956 1/1958 Rueger 346-741,028,037 5/1912 Lilleberg 178-30 BERNARD KONICK, Primary Examiner.

A. I. NEUSTADT, Assistant Examiner.

1. A MAGNETIC TRANSDUCER FOR INSTANTANEOUSLY RECORDING MAGNETIC IMAGESOR CHARACTERS ON A MAGNETIC SURFACE, COMPRISING: (A) A PLURALITY OFCOMB-LIKE ELEMENTS OF HIGH MAGNETIC PERMEABILITY, EACH HAVING ALTERNATETINES AND NOTCHES ALONG ONE EDGE; (B) MEANS FOR HOLDING SAID COMB-LIKEELEMENTS IN STACKED RELATION, ONE OVER THE OTHER WITH THE TINES ANDNOTCHES FACING IN THE SAME DIRECTION; (C) ELECTRICALLY CONDUCTIVE MEANSTHREADED THROUGH CERTAIN OF THE NOTCHES IN THE SHAPE OF A CHARACTER ORIMAGE TO BE RECORDED; AND (D) MEANS FOR CONNECTING THE SAID ELECTRICALLYCONDUCTIVE MEANS TO A PULSE OF ELECTRICAL ENERGY THEREBY MOMENTARILY TOINDUCE A FLOW OF MAGNETIC FLUX ACROSS THE ENDS OF EACH NOTCH TRAVERSEDBY SAID PULSED ELEC-